Napoleon is credited for helping create nationalism, especially for groups who otherwise were very disunited, such as the Germans and Italians, and led to people feeling an ethnic kinship with others. How did this work before the Napoleonic Wars? Did a Serbian in the Austrian Empire feel any connection to a Serbian in the Ottoman Empire? Did a Pole in Prussia feel any connection to a Pole in Austria or Russia? Or did a Frenchman, an Englishman, or a Russian feel connected to others of their ethnicity/nationality within their nations outside of simply "living in the same nation?"
I can't say for other countires, but since your question mentions it, I think I can shed some light on development of nationalism in Russia.
The problem with discussions concerning nationalism through history is t odefine what exactly can be understood as nationalistic in different time periods. Even in modern times, as far as I am aware, there can be some ambiguations as to what exactly this term means. Although "modern"nationalism is usually considered to be born somewhere around 19th century, first glimpses of this phenomenon can be traced back somewhat earlier, with its form changing drastically. If by "nationalism" we understand people from different regions recognizing themselves as one unified country of Italy or Russia, then no, there was no connection as deep as such. Often, for a common man, there was very blurred line between frontier lands and different lords who generally behave in similar manner. However, even in Medieval periods it wasn't unheard of for people inhabiting specific territory to refer to themselves as being closely tied together, unlike possible foreigners.
Many researchers usually refer to Renessaince and conjugated years, broadly calling late 14th - early 16th centuries to be the birth of nationalistic movements. Simultaneously, this era is commonly perceived to be a great developmental shift in European history: feudal lords being hard pressed by ever strengthening state centralization together with big scientific leaps compared to previous several centuries. However, big divisive notions which helped people from different countries to recognize "us" from"them" existed previously, and from my own experience in dealing with Russia specifically it usually stems not only from purely cultural or ethnic differences, but also from religious nuances.
In Middle Ages, religion often played key role in defining one's life. Religion dictated how people should've behaved themselves and why exactly the society functioned in one given way and not the other. Clergy often possessed immense power, sometimes even wrestling with royalty for control. Priests and bishops were very important in lives of both common people and nobility, it wasn't out of ordinary for a king to consult the church for guidance. Similarly, differences in religion also formed the very exact line drawn between "us" and "them". Medieval Rus' chronicles and sources of their neighbours often describe each other by naming each other's dominating religion and not exactly giving out a lot of information about ethnic or religious traits. As early as 13th century, Rus' annals make very clear distinction between Orthodox and Catholic countries. Specifically, in description of battle of Neva river (1240) between prince Alexander and Swedish host, Novgorodian Chronicle calls Swedes "Romans from the north". In this instance"Romans" are not nationality or reference to Roman empire, but a key factor in understanding Swedish believes. Being "Roman" for a medieval Russian was equal to being a Catholic (because Rome was de jure religious capital of western Europe), and, while there were further possible subsections of people from different parts of "Roman lands", they were generally the same people - the ones who weren't Orthodox (unlike Orthodox Greeks, whom Russians recognized to be very different to other Europeans).
Generally the same attitude could be seen as dominating from the other side: Swedish sources do not consider Russians to be "Christians" since they were Orthodox, and often grouped them together with Baltic pagans. Another name, usually given to western foreigners in Russia, and coincidentally the one which actually persisted and took dominating position in coming centuries, was "German", mostly because Germans were the closest western Europeans to come in contact with Rus'. By 16th century Rus' chronicles, unless they aimed at describing specific locations, didn't draw any distinction between peoples of western Europe, preferring to call them all "Germans": for example, Germans from the land of Franks, or Germans of Sweden. They did, however, recognize their nearest western neighbours (Lithuanians and Poles) to be of different stock, but didn't make any further recognitions: both "Litva" (Lithuanian) and "Lyach" (Polish) are used interchangeably during this period. The only people from territories of Polish-Lithuanian Commomwealth worthy of different names were those living in modern day Belarus, referred to as "belaruszi"(Belorussians), precisely because they were Orthodox Slavs - not exactly "native" Russians from Moscow's point of view, but much closer to them than any other people.
Unified Russian state took active interest in incorporating Orthodox territories from neighbouring countries. This played huge role in wars waged by Russia against both PLC and Sweden in 17th century. One of the reasons given by tsar Alexei Romanov to start hostile actions against Poland on the onset of Thirteen Years War of 1654-1667 were "many grievances" inflicted upon Orthodox commonfolk from eastern Commonwealth's borders by Catholic feudals. This entire military endeavor was firstly recognized as holy war, a crusade waged by Orthodox community (which, coincidentally, was one and the same with Russia from Russian viewpoint) against western heathens. Same reasoning was used in Russo-Swedish war of 1656-1658: territories taken by Sweden during its previous wars with Russia were considered Russian property as long as there was any Orthodox populace to speak of. Thus, waging war against Sweden was, again, from Russian viewpoint, a conflict of people from Orthodox Russia and people of different faith: both Russians remaining in Swedish possession AND any other Baltic people practicing the same believes were to be "saved" from the enemy and relocated to Russian territories.
In short, nationalism pre-Napoleonic wars was very noticable, but it usually took different forms such as religion playing key factor in describing one's country instead of being part of the same ethnic group. I hope that cleared things a bit.
Sorry for possible formatting errors, Reddit app is trash and constantly bugs out.